1. Field of the Invention
The present invention relates to a tube-type light-emitting diode (LED) illumination lamp, and more particularly, to a tube-type LED illumination lamp that can increase a light diffusion angle by obliquely positioning a printed circuit board on which an LED is placed.
2. Discussion of Related Art
In general, a light-emitting diode (LED) has a smaller size, a longer lifetime, less power consumption, and higher energy efficiency than a conventional light source.
Accordingly, various illumination lamps using an LED as a light source have been developed, and tube-type LED illumination lamps which may replace existing fluorescent lamps have recently been suggested.
FIG. 1 is a perspective view illustrating a conventional tube-type LED illumination lamp. FIG. 2 is a cross-sectional view illustrating the conventional tube-type LED illumination lamp of FIG. 1. FIG. 3 is a view illustrating a light distribution curve of the conventional tube-type LED illumination lamp of FIG. 1.
Referring to FIGS. 1 and 2, the conventional tube-type LED illumination lamp is configured such that a printed circuit board 30, on which LEDs 40 are arranged at predetermined intervals, is mounted on a top surface of a support member 15 that is formed to be parallel to a seating surface of a heat dissipation cover 10.
However, in this configuration, since a light diffusion angle is less than that of a general fluorescent lamp, because the LEDs 40 have excellent light directivity, an illuminance at a side is low, as shown in FIG. 3 (refer to 2).
That is, although an LED has a high illuminance at a center, an overall illuminance (indoor illuminance) is disadvantageously low. To overcome this disadvantage, more illumination lamps have to be installed.